Scythe stones have been in use for the last few thousand years as we learned to grow grain and harvest it for later consumption. I have scythe stones in my study collection which are at least 200 years old. The Belgian Blue scythe stones are particularly useful not only for scythes and sickles but also for recurve blades. Use a curved stone for a curved blade.
This scythe stone is great for curved edges such as recurve blades and scythes. It is used wet and it works fast. They are 8″ long and about 1.5″ wide and definitely a handful of whetstone! $45 plus shipping